Railway traffic controlling apparatus



Sept. 18, 1945.

E, M. ALLEN 2 Sheets-Sheet 1 Filed Nov. 11, 1942 INVENi'OR fiaplMAllen a m H15 ATTORNEY A N m N N g3 QNA \Nm. L NN NM QS N N E G QR gm 8% Sept. 18, 1945. E. M. ALLEN RAILWAY TRAFFIC CONTROLLING APPARATUS 2 Sheets-Sheet 2 Filed Nov. 11, 1942 .m R wl lr Y 5% mm M m J QR. 1. F, mm m ,mwkm @H m Q Q A m W r T m n +1 v kw m w @Gfi g L A IMNNN [\MNN% t [I IL r1 T KN A a m ,fimfi Fm QEw m 51H QRH R 1, L A w E mwnl QNAU M; QNA QNIAH wm .& A

Patented Sept. 18, 1945 TRAFFIC CONTROLLING APPARATUS RAILWAY Earl M. Allen, Swissvale, Pa., assignor to The Union Switch 8: Signal Company, SWissvale, Pa., a corporation of Pennsylvania Application November 11, 1942 Serial No. 465,215 Claims. (01. 2ie 1e1).

in the reverse position, while a relatively lon release period is provided for the locking for high speed traflic movements over the track switch in the normal or main line position. If a distant signal for a home signal in an interlocking plant is not operated to display the proceed indication, but is controlled to display a stop or a caution indication while its home signal is controlled to display some indication other than stop, such a long release period is not necessary, and is therefore undesirable since it unduly delays operations of the interlocking apparatus.

One feature of my invention is the provision of a medium release period when a distant signal is controlled to display a caution or a stop indication while its home signal is controlled to display some indication other than stop. Thi medium release period is shorter than the long release period which is provided for high speed trafiic movements, but is longer than the short release period which is provided for low speed trafiic movements.

I shall describe a few forms of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view showing one form of apparatus embodying my invention, in which two distant signals are provided for a given home signal because there is less than braking distance between the home signal and its first distant signal; and Fig. 2 is a diagrammatic view showing a modified form of the apparatus of Fig. 1, in which there is full braking distance between a home signal and its distant signal, and hence only the one distant signal is necessary for the horn signal. g

Similar reference characters refer to similar parts in each of the views. 4

Referring first to Fig. 1, there is less than braking distance between a home signal 7; which governs trafiic movements in a given direction, which I shall assume is the eastbound direction, over a switch 8 of an interlocking plant, and the first eastbound signal in the rear of signal 1 which, as shown, is also a home signal 2 which governs traflic movements over a switch 3. In addition to arm A of signal 2, which serves as the first distant signal for home signal I, a second distant signal I is provided for signal I. Si'g nal I and arm A of signal 2 are both constructed so that they are capable of displaying the proceed, caution, and stop indications. A dwarf signal 6 governs trafiic movements over switch 8 in the reverse position, from a side track Z. Signals 4,. 5 and 9 corresponding to signals 1, 6 and 2, respectively, govern trafiic movements iii the opposite or westbound direction. The various signals shown in the drawings may be of any suitable design such, for example, as the semaphore or the searchlight type.

The rails of the stretch of track shown in the drawings are divided by insulated joints Ill to form track sections IT, 3T, 4T and RT. Each of these track sections is provided with a track circuit including a source of current such as a battery ll connected across the rails adjacent one end of the section, and a track relay,- designated by the reference character R preceded by the reference character for its section, connected across the rails adjacent the opposite end of the section.

The contacts operated bythe various relays, time element devices, levers and track switches are identified by numbers, each suchnumber having a distinguishing prefix from which it is separated. by a dash when the associated contact is shown apart from the relay or other device by whichit is operated. The prefix for each of these contact numbers comprises the reference character for the relay or other device by which the associated contact is operated. For example, contact IHD2l shown in the upper left-hand portion of Fig. 1 of the drawings, in the operating circuits for signal I, is identified by the number 2| which is separated by a dash from the prefix IHD which is the reference character for relay lI-ID by which this contact is operated.

Signals 6 and l are controlled by home relays 6H and. TH, respectively, only a portion of the control circuit for-relay 1H being shown, including a contact 32 of a signal lever TV which has" a normal position n and a reverse position 1. Relay 6H may be similarly controlled by a lever 6V which is not shown in the drawings.

Arm A- of signal 2 is controlled by a neutral relay AZH and by a polarized relay 2HD. Relay ZHD is controlled, in part, by a contact 4! closed in the 1- position of a signal lever 2V having a normal position n and a reverse position r. The polarity of energization of relay ZHD is controlled by contacts lI-I34 and 1H42 of relay 1H, so that relay ZHD is energized in a normal direction only if relay lH is energized.

Signal 1 is controlled by a polarized relay IHD in such a manner that signal I will indicate proceed only if arm A of signal 2 indicates proceed. A repeater relay AZPC which controls the polarity of energization of relay IHD is controlled by relays AZH and 2I-l'D in such a manner as to be energized only if arm A of signal 2 is controlled to indicate proceed.

Switch 8 is provided with an operating mechanism 8M which, as here shown, is controlled by a polarized switch control relay 8W. A normal switch indication relay 3NWP is so controlled by a contact I2 operated by switch 3 as to be energized only when switch 3 occupies the normal position. A reverse switch indication relay BRWP is so controlled by a contact 62 operated by switch 8 as to be energized only when switchB occupies the reverse position.

An approach or time locking stick relay, here shown as a time looking stick relay designated by the reference character TALS, controls, in part, the switch control relay 8W by means of a front contact 'IALSI3, so that relay 8W cannot be energized for eifecting operation of switch 8 unless relay 'IALS is energized.

Only a portion of the normal and reverse control circuits for relay 8W is shown in the drawings. The portions of these circuits which are not shown maybe controlled in any suitable manner such, for example, as by a lever operated by a leverman in the interlocking tower.

Energization of locking stick relay TALS is controlled, in part, by time element means here shown as two thermal devices BlTE and AlTE, by two slow release stick relays lTES and STES designatedfirst and third auxiliary stick relays, respectively, by a second auxiliary or short time release stick relay lWZ, and by a medium time release stick relay AZPP.

' Referring now to Fig. 2, a medium time release stick relay AZHP is here shown controlled by relays -A2H and ZHD instead of by relay AZPC as is shown for relay AZPP in Fig. 1. Relay AZHP here controls the second time element device AETE and a medium time release circuit for relay EALS similarly to the manner shown for relay AZPP in Fig. 1. Other parts of the apparatus of Fig. 2 are controlled as in Fig. 1.

Having described, in general, the arrangement and control of the apparatus, I shall now describe, in detail, its operation.

As shown in the drawings, allparts are in the normal condition, that is, switches 3 and 8 are in their normal positions; signal I is indicating caution, and all other signals shown in the drawings are indicating stop; normal switch indication relay 3NWP is energized; switch control relay BW is energized; switch mechanism GM is retained in its normal position by a circuit controlled by relay 8W; relay IHD is energized by current of reverse polarity, and hence signal I is indicating caution; stick relays 'IALS, AZPP and AZHP ar energized; and relays 8RWP, 6H, 1H, A2I-I, 2HD,'A2PC, lWZ, 'ITES, STES, and time element devices ATIE and BITE are deenergized. With switch 3 in the normal position, normal switch indication relay 3NWP is energized by a circuit passing from terminal B of a suitable source of current, through contact l2 of switch 3 in the normal position, and the winding of relay 3NWP to terminal 0 of the same source of current.

Relay 8W is shown energized by current of normal polarity by a circuit, only a portion of which is shown, including contact lALS-l 3. The mechanism 8M of switch 8 is retained in the normal position by a circuit passing from terminal B, through contacts I4 and [5 of relay 8W, and mechanism 8M to terminal 0.

Relay IHD is energized by current of reverse polarity in a circuit passing from terminal B, through the back point of contact l6 of relay A2PC, the winding of relay IHD, contacts lTR-ll and 3TRI3, contact |9-of a relay AALS which may be controlled similarly to relay IALS,

and the back point of contact 29 of relay AZPC to terminal 0. With relay iHD energized by current of reverse polarity, signal 1 is retained in the caution position by a circuit, only a portion of which is shown, including contact IHD-2 Relay 'IALS is energized by a stick circuit passing from terminalB, through contacts 'lH-22 and 61-1-23, front point of contact 24 of relay 'IALS, and the winding of relay 'IALS to terminal O.

With relay IALS energized, a pick-up circuit is closed for relay A2PP passing from terminal B. through contact 25 of relay A2PC, contact 'IAL'S26, and the winding of relay A2PP to terminal O. A stick circuit for relay AEPP is also closed, which is the same as the pick-up circuit just traced, except that it includes contact 21 of relay AZPP instead of contact TALS-ZS.

Relay AZHP, shown in Fig. 2, is energized by pick-up and stick circuits including contacts A2H28 and 2HD29 in multiple. The pick-up circuits also include contact TALS3Q, and the stick circuits include contact 3| of relay AZHP.

I shall assume that with switches 3 and 8 in the normal position, as shown, a leverman arranges for an eastbound high speed traflic movement over the main line by placing signal levers 2V and 1V in their 1' positions in the scheme shown in Fig. 1.

With lever 1V in its 1' position, its contact 32 will be closed in the portion of the circuit shown for energizing relay 1H. The arm of signal 1 will therefore be controlledto indicate caution by a circuit, a portion of which is shown, including contact 33 of relay 1H. By meansof a distant relay, not shown, the arm of signal 1 may then be controlled to indicate proceed. 7

With lever 2V in the 1 position, and with relay 1H energized, a circuit will be completed for energizing relay ZHD by current of normal polarity, passing from terminal B,'through front point of contact 11-1-34, 'cont'act 8TR-35, contact 36 of relay 9ALS, contacts 4ALS38, 4TR39 and 3TR-4!J, contact 4| of lever 2V closed in the r position, winding of relay 2HD, and the front point of contact !I-I 42 to terminal 0. With relay 2I-ID energized, a'circuit, only a portion of which is shown, will be completed for energizing relay AZH, including contact 3NWP-43 and contact ZED-44, and the'winding'of relay AZH to terminal 0. With relay AZH energized, and with relay 2HD energized by current of normal polarity, arm A of signal 2 will be operated to the proceed position by a circuit including'ccntactrfid of relay AZH, contact ZED-'55, and the mechanism of arm A of signal 2.

With relay AZH energized, and with relay ZHD I energized by current of normal polarity,-a circuit contact A2I-I45, contact 46 of relay 2m), and the winding of relay AZPC to terminal 0.

With relay AZPC energized, the circuit pre- Viously traced for relay il-ID will be pole changed by contacts l6 and 2a of relay AZPC to energize relay IHD by current of normal polarity. The arm of signal I will therefore be operated to the proceed position by a circuit including contact |HD-2|, contact |I-IDM, and the mechanism of signal I to terminal 0.

With relay AZPC energized, the pick-up and stick circuits previously traced for relay AZPP will be opened at contact 25 of relay AZPC, causing relay AZPP to be deenergized.

- Relay ll-I, upon becoming energized, opens its contact '!H22, thereby breaking the stick circuit previously traced for relay 'lALS and causing relay lALS to become deenergized.

I shall now assume that an eastbound train moves over the stretch of track shown, and passes signal 1. If new relay 7H becomes deenergized, either by a contact of relay 8TB, not shown, in the circuit for relay 7H, or by the leverman returning lever 7V to the 12 position and thereby opening contact 32 in the circuit for relay 1H, a

pick-up circuit will be completed for relay 'IALS, passing from terminal B, through contacts III-J2, %H 23, Bl'TEdt, A'iTE-49, 8TR -u, and the winding of relay 'EALS to terminal 0.

With relay 'FALS thus energized, relay 8W can become energized by current of reverse polarity for efiecting operation of switch 8 to the reverse position, if desired, after the train leaves section 8T.

I shall assume that all parts of the apparatus are returned to the normal condition after the eastbound train passes over the stretch of track shown, and that the leverman again arranges for a high speed trafiic movement by placing signal levers 2V and 1V in the 1" position for clearing signal I and arm A of signal 2. I shall further assume that the leverman returns the arm of signal 1 to the stop position before the eastbound train passes this signal.

With. contact 8TR5EI open, relay 'IALS will remain deenergized, but a circuit Will be completed for energizing the first time element device BITE, this circuit passing from terminal B,

through contacts '|II-22 and Gil-23, back point of contact 24 of relay 'iALS, back point of contact 5| of relay T'IES, and time element device BITE to terminal 0. Upon the lapse of a measured period of time after the completion of this circuit, contact 52 of device B'ETE will complete a pick-up circuit for energizing relay 'I'IES, which is the same as the circuit previously traced for time element device BITE except that it includes contact 52 of device BYTE instead of the back point of contact 5| of relay lTES. Relay 1TES, upon becoming energized, completes its stick circuit which is the same as its pick-up circuit just traced except including the front point of contact 5| of relay FTES instead of contact 52 of time element device BITE. Relay ITES, upon opening the back point of its contact 5|, deenergizes time element device BITE which then starts to cool. I

With relay l'TES energized, a circuit is completed for energizing the second time element device A'ITE, which is the same as the stick circuit for relay 'l'I'ES as far as the front point of contact 5| of relay ITES, and then passes through the .back point of contact 53 of relay BTES, contact A2PP54, and time element device A'I'I'E' toterminal 0. Upon the lapse of a measured period of time after the completion of this circuit, contact 55 of time element device A'ITE will be closed, completing a pick-up circuit for relay STES which is the same as the stick circuit for relay 'I'IES as far as the front point of contact 5| of relay ITES, and then passes through contact 55 of time element device ATTE, and the winding of relay BTES to terminal 0. Relay QTES, upon becoming energized, completes its stick circuit which is the same as the pick-up circuit just described except including the front point of contact 53 of relay QTES instead of contact 55 of time element device AITE. Relay QTES, upon becoming energized, opens, at the back point of its contact 53, the circuit previously traced for time element device A'ITE, and thus causes device A'lTE to start to cool.

When time element device A'ITE has cooled sufiiciently, a second pick-up circuit will be com pleted for relay 'IALS passing from terminal B, through contacts 1H-22, 6H--23, B'I'IE48, A'lTE-49, 9TES56, and 1TES-60, and the winding of relay TALS to terminal 0.

I shall next asswnethat all parts of the apparatus are again returned to the normal condition and that the leverman places lever 1V in the 1* position for controlling signal 1 to display the proceed or caution indication depending on whether its distant control relay, which is not shown, is energized or deenergized, but that before he clears arm A of signal 2, he decides to set up a difierent route. He therefore does not move lever 2V to its 1' position, and hence relays ZHD and A2H do not become energized. Relay AZPP therefore remains energized by its stick circuit previously traced.

In order to arrange a difierent route, the leverman Will restore lever IV to the n position, thereby deenergizing relay 1H and completing the energizing circuit previously traced for time element device B'ITE. Relay 'ITES will become energized as previously described, but time element device AITE will not become energized because contact A2PP54 will now be open.

As soon as time element device BITE has cooled sufficiently after the opening of contact 5| of relay 1TES at its back point, a third pick-up circuit will be completed for energizing relay IALS, constituting a medium time release circuit. This circuit passes from terminal B, through contacts 1H22, 61-1-23, B1TE48, back point of contact 8RWP-5l, contacts A2PP58 and lTES-BO, and the Winding of relay 1ALS to terminal 0.

I shall next assume that all parts of the apparatus are again returned to their normal condition, and that the leverman decides to direct a train to move from siding Z to the main line over switch 8 in the reverse position. He will therefore energize relay 8W by current of reverse polarity which will then complete a reverse operating circuit for switch operating mechanism 8M passing from terminal B, through contact l4 of relay 8W, contact l5 of relay 8W in the reverse position, and mechanism 8M to terminal 0.

The leverman will then energize relay 6H by opcrating its lever, corresponding to lever 1V shown for signal I, to the r position. Signal 6 will then be cleared by its circuit including contact 6| of relay 6H. Relay 6H, upon becoming energized, will deenergize relay 'IALS by opening its contact 6H23.

I shall further assume that before the train passes signal 6, the leverman decides to arrange a different route. He will therefore return signal 6 to stop by deenergizing relayGH... With switch 8 in the reverse position, reverse switch indication'relay BRWP will be energized, by its circuit passing. from terminal B, through contact. 62 of switch 8, and the winding of relay SRWP-to terminal 0.

When the leverman deenergizes relay (H, a

pickup circuit will therefore be completed for energizing the short time release stick relay'IWZ, thiscircuit passing from terminal B,- through contacts TIL -22, 6I-I- 23, and Bl'I'E.48, front point of contact 8RWP5 1, and the winding of relay 'IWZ to terminal 0... Relay 'IWZ, upon thus becoming energized, will complete its stick circuit passing from terminal B, through contacts III-22 and BIL-Z3, contact 63 of relay IWZ, and the winding of relay 'IWZ to terminal 0. With relay 6H deenergized, the energizing circuit for time element Idevice BITE will be completed as previously traced.

' As .soon as relay 'ITES becomes energized, a fourth or short time release circuit will be completed for relay 'IALS passing from terminalB, through contacts |H22, and 6I-I23, contact 59 of relay 'IWZ, contact 7TESB0, and the winding of relay 'IALS to terminal 0.

v I shall now assume that all parts of the apparatus are again returned to the normal condition, and that the leverman again clears signal 6 for a traffic movement from siding Z over switch 8 in its reverse position, and that he again returns signal 6 to stop before a train passes this signal. I shall further assume that hethen again clears signal 6 but again quickly returns it to the stop indication. By returning signal 6 to stop the first time, the heating of time element device BITE has been begun, and then the clearing of signal 6 deenergizes relay 'IWZ which cannot now again pick up because back contact BITE-48 is open due to the heating of time element device B'ITE when signal 6 was first returned to the stop indication.

Therefore, when the leverman returns signal 6 to the stop indication the second time, the circuit will. again be closed for energizing time element device BYTE. and continuing it to the condition in which its contact 52 closes the pick-up circuit for relay 'ITES. Device B'ITE will then be deenergized by the opening of the back point of contact 5! of relay iTES. Upon the lapse of a measured period of time, contact B'iTE-48 will complete the pick-up circuit previously traced for relay 'IWZ. The short time release circuit previously traced for relay IALS will then again be completed.

. ,It follows that, the leverman clears signal 6 for alow speed trafficmovement and then puts it to stop, and then again clears signal 6 and again returns it to the stop indication after time element device BITE has started to heat, but before a train has passed signal 6, protection is provided against a reduction of the time of energization of relay 'l'ALS by the short release circuit.

In the form of aparatus shown in Fig. 2, the circuits for relay A2HP are controlled directly by contacts of relays AZI-I and ZHD instead of by relay AZPC which is in turn controlled by these two relays, as shown in Fig. 1. Relay A2I-IP'of Fig. 2 is therefore energized, similarly to relay AZPP of Fig. 1, only if signal A2 is controlled to indicate stop or caution, causing contact A2H- 28 or 2HD-29 in the circuits for relay AZHP to be closed, and becomes deenergized if arm A of signal 2 is controlled to indicate proceed because then, relay AZH will be energized and relay 2HD will be energized by current of normal polarity causing its contact 2HD-29 in the circuits for relay A2HP to be opened. The operation of the form of apparatus shown in Fig. 2 for providing a medium time release of the locking will, therefore, be understood in view of the foregoing description of the operation of the apparatus of Fig. 1 for providing medium time release of the lockmg.

From the foregoing description and the accompanying drawings, it follows that, in apparatus embodying my invention, I have devised means for providing three different time periods for releasing approach or time looking in a railway interlocking control system. A longrelease period is provided if a, distant signal is controlled to indicate proceed while its home signal is controlled to display an indication other than stop; a medium release period is provided if a distant signal is controlled to indicate other than proceed while its home signal is controlled to display an indication other than stop; and a short release period is provided if a low speed route is arranged for a traffic movement over a switch in the reverse position. Two time element devices and two slow release stick relays controlled by the time element devices, and also a short time release stick relay and a medium release stick relay are included in the apparatus for accomplishing these results.

Although I have herein shown and described only a, few forms of railway trafiic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is 1. In release means for energizing an approach or time looking stick relay in a railway interlocking control system, including a time element device, including a first slow release auxiliary stick relayand a second auxiliary stick relay, including means for energizing said second auxiliary stick relay if said time element device is deenergized and if a given track switch is in the reverse position, including an energizing circuit for said time element device controlled by back contacts of said locking stick relay and said first auxiliary stick relay, including means for energizing said first auxiliary stick relay if said looking stick relay is deenergized and if said time element device is energized, the combination comprising, a second time element device slow to pick up and slow to release, a third auxiliary stick relay slow to release, an energizing circuit for said second time element device controlled by a front contact of said. first auxiliar stick relay and by a back contact of said third auxiliary stick relay, a pick-up and a stick circuit for said third auxiliary stick relay both controlled by a front contact of said first auxiliary stick relay and the pick-up circuit controlled also by a front contact of said second time element device, a pick-up circuit for said locking stick relay controlled by back contacts of both said time element devices and by front contacts of said first and third auxiliary stick relays, and a second pick-up circuit for said locking stick relay controlled by front contacts of said first and second auxiliary stick relays.

2. Release means for energizing an approach or time looking stick relay in a railway interlocking control system including a signal for governing low speed traffic movements over a given track switch and including a second signal for at times governing medium speed traflic movements and forat other times governing high speed traific movements over said switch, comprising in combination, a circuit becoming closed for energizing said stick relay upon the lapse of a short period of time after said first signal becomes controlled to indicate stop after having been cleared to direct a low speed traflic movement over said switch, a second circuit controlled to .beco'me closed only if said first circuit is open for energizing said stick relay upon the lapse of a medium period of time after said, second signal becomes controlled to indicate stop after having been cleared for directing a medium speed trafiic movement over said switch, and a third'circuit controlled to become closed only if said second circuit is open for energizing said stick relay upon the lapse of a long period of time after said second signal becomes controlled to indicate stop after having been cleared for directing a high speed trafiic movement over said switch.

3. Means for releasing approach or time looking apparatus in a railway interlocking control system including a signal for governing a train moving at low speed toward a given section of track and including a second signal for at times governing a train moving at medium speed and for at other times governing a train moving at high speed toward said given section of track, comprising in combiation, means for releasing said locking apparatus upon the lapse of a short period of time after said first signal becomes controlled to indicate stop after having been cleared to direct a train moving at low speed toward said given section of track, other means effective only if said first means is ineffective for releasing said locking apparatus upon the lapse of a medium period of'time after said second signal becomes controlled to indicate stop after having been cleared to direct a train moving atmedium speed toward said given section of track, and still other means eifective only if said other means is ineffective for releasing said locking apparatus upon the lapse of a long period of time after said second signal becomes controlled to indicate stop after having been cleared to direct a train moving at high speed toward said given section of track.

4. In release means for energizing an approach or time looking stick relay in a railway interlocking control system, in which a time element device is controlled by back contacts of the locking stick relay and of a slow release auxiliary stick relay, in which said auxiliary stick relay is controlled by a front contact of said time element device and by a back contact of said locking stick relay, in which a second auxiliary stick relay has a pick-up circuit controlled by a back contact of said time element device if a given track switch is in the reverse position and has a stick circuit which then remains closed as long as an associated signal is controlled to indicate stop, the combination comprising, a second time element device slow to pick up and slow to release, a third slow release auxiliary stick relay, an energizing circuit for said second time element device controlled by a front contact of said first auxiliary stick relay and by a back contact of said third auxiliary stick relay, a pick-up and a stick circuit for said third auxiliary stick relay controlled by front contacts of said second time element device and of said first auxiliary stick relay respectively, a pick-up circuit for said locking stick relay controlled by back contacts of both said time element devices and by front contacts of said first and third auxiliary stick relays, asecond pick-up circuit for said locking stick relay controlled by front contacts of said first and second auxiliary stick relays, and a third pick-up circuit for said locking stick relay controlled by a back contact of said first time element device and by a front contact of said first auxiliary stick relay.

5: In release means for energizing an approach or time looking stick relay in a railway interlocking control system; in which a time element device is controlled by back contacts of the looking stick relay and of a slow release auxiliary stick relay, in which said auxiliary stick relay is controlled by a front contact of said time element device and by. a back contact of said looking stick relay, in'which a second auxiliary stick relay has a pick-up circuit controlled by a back contact of said time element device if a given track switch is in the reverse position and has a stick circuit which then remains closed as long as an'associated signal is controlled to indicate stop, the combination comprising, a second time element device'slow to pick u and slow to release, a third slow release auxiliary stick relay, an energizing circuit for said second time element device controlled by a front contact of said first auxiliary stick relay and by a back contactof said third auxiliary stick relay, a pick-up and a stick circuit for said third auxiliary stick relaycontrolled by front contacts of said second time element device and of said first auxiliary stick relay respectively, a pick-up'circuitfor said locking stick relay controlled by back contacts of both said time element devices and by front contacts of said first and third auxiliary stick relays, a second pick-up eircuitfor said locking stick relay controlled by front contacts of said first and second auxiliary stick relays, and a third pick-up circuit for said locking stick relay controlled by a back contact of said first time element device and by a front contact: of said first auxiliary stick relay if the track switch is in the normal position and if a distant signal for an associated home signal has not been controlled to indicate proceed.

6. In release means for energizing an approach or time looking stick relay in a railway interlocking control system, including means for energizing said locking stick relay upon the lapse of a relatively long period of time after an associated home signal is controlled to indicate stop, the combination comprising, a medium release stick relay, a pick-up and a stick circuit for said medium release stick relay each of which is closed only if a distant signal for said home signal is controlled to display an indication other than proceed and said pick-up circuit also including a front contact of said locking stick relay, and, a circuit including a front contact of said medium release stick relay for energizing said locking stick relay upon the lapse of a medium period of time after said associated home signal is controlled to indicate stop.

7. In release means for energizing an approach or time looking stick relay in a railway interlocking control system, including a time element device, including means controlled by said locking stick relay for energizing said time element device when an associated home signal is controlled to display the stop indication after having been controlled to display some other indication, the combination comprising, a second time element device, means controlled by said first time element device upon the lapse of a measured period of time after it becomes energized for energizing said second time element device, a circuit con"- trolled by said first and second time element devices upon the lapse of a second measured period of time after said second time element device becomes energized for energizing 'said locking stick relay, and a second circuit controlled by said first time element device for energizing said locking stick relay if a distant signal for said home signal has displayed the stop or caution indication while the home signal displayed an indication other than stop and thereby providing a shorter release time than is provided by said first circuit;

8. In release means for energizing an approach or time locking stick relay in a railway interlocking control system, including a time element device, including means controlled by said looking stick relay for energizing said time element device when an associated home signal is controlled to display the stop indication after having been controlled to display some other indication, including a short release circuit controlled by the pick-up operation only of said time element device for energizing said locking stick relay if a given track switch is in the reverse position, the combination comprising, a second time element device, means controlled by the pick-up operation of said first time element device for energizing said second time element device, a long release circuit responsive to the pick-up and release operations of both said time element devices for energizing said locking stick relay, and a medium release circuit responsive to the pickup and release operations of only said first time element device for energizing said locking stick relayif a distant signal for an associated home signal has continued to display the stop or caution indication while the associated home signal was controlled to display an indication other than stop.

9. In release means for energizing an approach or time looking stick relay in a railway interlocking control'system, including means'for'energizing said locking stick relay upon the lapse of a relatively long period of time after an associated home signal is controlled to indicate stop, the combination comprising, a, medium release stick relay, means for normally energizing said medium release stick relay but for deenergizing it if a distant signal for an associated home signal is controlled to display the proceed indication, and a circuit controlled by a front contact of said medium release stick relay for energizing said locking stick relay upon the lapse of a shorter period of time than is provided by said long release means;

10. In release means for energizing an approach or time looking stick relay in a railway interlocking control system, including a time element device, including means controlled by said locking stick relay for energizing said time element devicewhen an associated home signal is controlled to display the stop indication after having been controlled to display some other indication, the combination comprising, a second time element device, means responsive to the pick-up operation of said first time element device for energizing said second time element device only if a distant signal for said associated home signal has been controlled to display the proceed indication while said associated home signal displayed an indication other than stop, long release means responsive to the pick-up and release operations of both said time element devices for energizing said locking stick relay, and shorter release mean responsive to the pick-up and release operations of only said first time element device for energizing said locking stick re lay if the distant signal for said associated home signal has continued to display an indication other than proceed while said associated home signal displayed an indication other than stop.

EARL M. ALLEN. 

